It is known that a flight plan generally comprises waypoints to be flown over by the aircraft, information (altitude, speed, etc.) relating to such waypoints, as well as information concerning branches between the different waypoints. Such a flight plan allows a flight trajectory to be built comprising a lateral trajectory defined in the horizontal plane and a vertical trajectory (or vertical profile) defined in the vertical plane.
The present invention more particularly aims at the field of navigation and relates to a flight management functionality relating to a flight management system of the Flight Management System (“FMS”) type. Such a system allows to plan, to manage, as well as to predict the flight, both in the horizontal plane and the vertical plane. More particularly, the present invention relates to the architecture of the elements intended for managing the vertical flight plane (vertical profile).
In order to aid piloting upon flights of civil and military aircrafts, different types of operations could be defined, each of said operations enabling to carry out one or more particular instructions. For instance, in the civil field, there is an operation allowing for a flight at constant Mach between two points (referred to as Constant MACH Segment (“CMS”) from the expression CMS), and an operation concerning a change of altitude from a particular point (referred to as STEP FROM). In the military field, it is possible to carry out tactical operations such as a constant speed flight between two points, a flight at constant altitude and speed between two points, a change of altitude toward a particular point (referred to as STEP TO), as well as other specific military operations such as a drop (DROP) or an air to air refuelling in flight (Air to Air Refueling (“AAR”).
Each of such operations is independently managed by the flight management system and has specific and different properties and rules.
Thus, the issue associated with the definition of the vertical profile results from:                the multiplicity of possible maneuvers, due to various military or civil operations, involving the definition of specific rules for managing each one of them;        the combinatorics resulting from sequences and superpositions of these different operations; and        the impossibility to manage the transitions between two successive levels, reducing the possibilities of military applications.        
In addition, different operations could sometimes at least be partially superimposed (for instance a constant speed segment could be superimposed, in part, to a climbing phase), increasing the complexity of the situation and making difficult the definition of a system being robust in every situation able to be met.
Because of the sequence of multiple elements of the flight plan, for military and civil operations, a combinatorics problem thus occurs. Indeed, each element of the flight plan has its own complexity, its own implementation (specific and dedicated algorithms), making it a single entity. For example, a change of level depends on two parameters being the starting waypoint of the change of level and the altitude of the level to be reached. Conversely, a constant Mach segment depends on two (starting and ending) waypoints, as well as the Mach instruction between these waypoints. As a result, the succession of these different phases becomes more complex as long as an evolution occurs at the level of these operations. If new types of operations are added or some characteristics of these operations are modified, the whole sequence of phases should be reviewed.
For example, during the sequence of an air refuelling in flight and of a drop, for instance, it becomes complex to define an adequate transition, each element having its own features and transitions.
Besides the complexity added by the military phases, the issue is also linked to the impossibility to manage the transition phases. These transition phases are necessary in military operations and more particularly in the sequence of the latter. For instance, upon a drop, it is sometimes necessary to check the climbing/descent slope toward the dropping altitude so as not to disturb the preparation of the drop (for preventing items to be dropped from sliding or paratroopers from loosing their balance).
Furthermore, the elements of the flight plan existing in the civil field do not allow to manage the transitions between levels. Thus, generalizing civil modes to the military field would result in an additional complexity because of the additional phases to be managed. Indeed, the impossibility to manage the transitions is not adapted to the military field requiring particular transitions for implementing the different flight phases. Such an evolution considerably complicates implementing the elements of the flight plan and sequencing these elements both for the pilot and for the system that should manage the flight plan (also involving an increased complexity in the development of the FMS system with a multiplicity of algorithms). Consequently, the solutions existing in the civil field are not adapted to military applications and do not allow to satisfactorily manage the two types of flight plan at the same time.
Furthermore, it is known:                from document US-2003/0139877, a method and a device for assembling a flight plan;        from document U.S. Pat. No. 6,389,355, a method and a device for displaying and editing a flight plan;        from document US-2010/0250026, an interactive navigation device, comprising at least one navigation display able to display a representation of the flight plan; and        from document WO-02/25214, a graphic system and a method for defining requests from pilots.        
The present invention relates to a method for automatically managing the vertical profile of a flight plan of an aircraft, in particular a transport airplane, comprising waypoints to be flown over by said aircraft, allowing the above mentioned drawbacks to be overcome.